In this short summary we will try to explain what is the nautical neddle in a boat:
NAUTICAL NEEDLE

1. Description: A magnetic needle which tends to indicate the same magnetic direction and permanently maintain it. It is basically made up of a series of magnets placed at the bottom of a light disc (pink), where they recorded the 360 ​​° of the horizon; in the center of the rose there is a gap (chapitel) which is where it rests on the tip of the style that is firm to the mortar, which is the metal box containing the entire set and where the lines of faith that match with the fore-aft line, it topped with a glass cover. The mortar, resting on a suspension system called Cardan, is placed in a kind of cabinet called log.

2. Installation It is recommended to be installed on the center line and the line of faith will indicate the fore-aft direction. It must be clearly visible throughout the helmsman from the main steering position time.

3. Disturbances: The needle is subject to perturbations due to alterations of the usual magnetic field, and is sensitive to the proximity of magnetized objects (knives, belt buckles, watchbands, etc.), electrical appliances (speakers, motors , radio equipment, probes, etc.) and thunderstorms. I